This invention relates to a ropeless linear motor elevator system in which an elevator car can be vertically moved within a hoistway by a propulsion force of a linear motor without using a rope.
FIG. 4 is a schematic diagram illustrating a conventional ropeless linear motor elevator system similar to that disclosed in Japanese Utility Model Laid-Open No. 62-136476.
In the figure, a plurality of coils (2) are disposed in vertical arrays and vertically extending rails (3) are mounted on each side wall of a hoistway (1). On each side of an elevator car (4) which moves up and down along the rails (3) within the hoistway (1), a plurality of permanent magnets (5) are mounted in opposition to the coils (2).
In the conventional ropeless linear motor elevator system as described above, the coils (2) and the permanent magnets (5) constitute a synchronous linear motor, which generates a linear motor propulsion force for vertically driving the car (4) along the rails (3).
In the conventional ropeless linear motor elevator system, there is no emergency brake mechanism for braking the car in an emergency such as when the propulsion force abnormally decreases due to a fault or the like, so the safety of the system is not completely satisfactory. Therefore, the conventional ropeless linear motor elevator system which has inadequate safety is difficult to put into practical use.